Piezoelectric Drive Feedback for Stable Liquid Ejection
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Solution Overview
Problem
The piezoelectric properties of piezoelectric bodies in liquid ejecting apparatuses change over time due to continuous printing, leading to variations in liquid ejection amounts and potential color differences, affecting printing quality.
Innovation Solution
A method involving the generation of pairs of drive signals with varying electrical potential differences and detection of residual vibration signals to identify the deformation properties of piezoelectric elements, allowing for correction of drive signals to maintain consistent ejection performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If drive voltage is set based on piezoelectric properties measured during manufacture, then initial ejection performance is good, but ejection amount changes over time as piezoelectric properties degrade
Solution Approach 1:
The system applies a predetermined drive signal to the piezoelectric element and detects the resulting residual vibration signal. By analyzing the frequency characteristics of this residual vibration, the system identifies deformation properties of the piezoelectric element and uses this feedback information to correct future drive signals, thereby compensating for degradation and maintaining consistent ejection performance over time.
Solution Approach 2:
The system changes the drive signal parameters based on identified deformation properties. Specifically, it adjusts the drive voltage or drive waveform parameters according to the detected changes in piezoelectric element characteristics, allowing the system to adapt to degradation and maintain reliable operation.
2Device complexity
If piezoelectric properties are assumed constant after manufacture, then device complexity is low, but measurement precision of current state deteriorates
Solution Approach 1:
The system uses the piezoelectric element's own residual vibration response to self-diagnose its deformation properties. By applying a drive signal and analyzing the resulting vibration signal from the same element, the system identifies current state without requiring external measurement equipment, thereby maintaining low device complexity while achieving accurate measurement of current piezoelectric properties.
3Ease of operation
If drive signal is not corrected for degradation, then ease of operation is high, but printing quality deteriorates due to color differences
Solution Approach 1:
The system performs preliminary identification of deformation properties by applying a predetermined drive signal and analyzing residual vibration characteristics before actual printing operations. This preliminary characterization allows the system to pre-correct drive signals, ensuring printing quality is maintained without requiring complex real-time adjustments during operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables accurate identification of piezoelectric element degradation and correction of ejection amounts, reducing the likelihood of color differences and maintaining printing quality over time.
Implementation Method 1
The piezoelectric body deforms according to an applied drive voltage, that is, a difference in electrical potential between an upper electrode film and a lower electrode film. The deformation of the piezoelectric body is used to cause a fluctuation in the pressure applied to the ink in the pressure chamber and thereby cause a droplet to be ejected from the nozzle.
Implementation Method 2
a detector that detects, as residual vibration signals for the respective pairs, variations in electromotive force of the piezoelectric element according to variations in residual pressure applied to liquid in the pressure chamber
Data Source
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AI summary
A method of driving a liquid ejecting apparatus including a piezoelectric element, and a pressure chamber. The method includes: generating a plurality of pairs of first drive signals and second drive signals, the first drive signals include electrical potential-changing elements that change in electrical potential, and the second drive signals that include electrical potential-maintained elements that maintain fixed electrical potentials, and detecting , as a plurality of residual vibration signals for the plurality of pairs, variations in electromotive force of the piezoelectric element according to variations in residual pressure that is applied to liquid in the pressure chamber after every supplying the electrical potential-changing element and the electrical potential-maintained element to the piezoelectric element for the plurality of the pairs, and identifying a first deformation property of the piezoelectric element based on the plurality of residual vibration signals for the plurality of pairs.